The present invention relates to forming a part with an integrally formed attachment device via selective laser sintering or the like.
Prior art pipes may be fabricated with flanges which are bolted together with nuts and bolts. In particular, the flanges of two mating prior art pipes may have a plurality of bolt holes about a periphery of the flanges. The bolt holes of a first pipe flange correspond, or otherwise, have the same pattern of bolt holes as the flange of a second pipe. The pipe flanges of the first and second pipes are aligned to each other, and bolts are inserted through the bolt holes and screwed onto a nut. The bolts and nuts apply clamping pressure onto the flanges to join the pipes together.
Once the pipes are joined together, they are typically disassembled and reassembled during maintenance or failure. During disassembly, maintenance personnel must remove the bolts and the nuts from each of the bolt holes. Further, maintenance personnel must keep track of the bolt and nut combination for each flange. In a large pipe system, the number of bolts and nuts may be enormous such that keeping track of all the nuts and bolts is too difficult or impossible.
To aid maintenance personnel, nut plates may be used to permanently retain the nut next to its bolt hole in an aligned position such that the bolt may be removed from the nut without having to keep track of the nut. In particular, the nut plate may have two opposed retaining holes, and the nut may have two outwardly protruding spring clips. The spring clips are inserted into the retaining holes to retain the nut on the nut plate. Since the nut plate is attached next to the bolt hole, the nut is also retained next to the bolt hole. Accordingly, during maintenance or repair, when the bolts are removed from the nuts, the nuts remain next to the bolt holes such that the nuts are not lost. The nut plates also help maintenance during disassembly and reassembly of pipes when nuts are located behind a wall or a place where the nuts cannot be reached by maintenance personnel.
Unfortunately, there are a few disadvantages with this nut plate system. The nut plate is typically attached to the pipe flange with two rivets. To this end, the rivets are inserted into two holes formed in the nut plate as well as the flange. The holes in the flange weaken the flange by causing stress concentrations therein. Another disadvantage with this system is that time is required to attach the nut plate to the pipe flange thereby increasing initial assembly cost of the pipe system.
Accordingly, there is a need in the art for an improved method and apparatus.